<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>按钮</title>
    <style>
        .btn {
            color: white;
            border: none;
            height: 34px;
            font-size: 14px;
        }

        .btn-success {
            background-color: #5cb85c;
        }

        .btn-warning {
            background-color: #f0ad4e;
        }

        .btn-danger {
            background-color: #d9534f;
        }
    </style>
</head>

<body>
    <!-- button 行内快元素 -->
    <button class="btn btn-success">确定</button>
    <button class="btn btn-warning">确定</button>
    <button class="btn btn-danger">确定</button>
</body>

</html>